Process for redistillation of products of destructive distillation.



HAROLD M. CHASE AND JOHN L. GRAFFLIN, OF WILMINGTON, NORTH CAROLINA,

ASSIGNORS TO NATIONAL W001 DISTILLING COMPANY, OF WILMINGTON,

' NORTH CAROLINA, A CORPORATION OF NORTH. CAROLINA. r

IROCESS FOR REDISTILLATION OF PRODUCTS 0]? DESTRUCTIVE DISTILLATION.

No Drawing.

T 0 all whom it may concern:

Be it known that we, HAROLD M. CHASE and JOHN L. GRAFFLIN, both citizens of the United States, residing at Wilmington, in

the county of New Hanover, State of North Carolina, have invented certain new and useful Improvements in Processes for Bedistillation of Products of Destructive Distillation, of which the following is a description. A

Our invention relates to a process of redistillation of products produced from resinous wood by destructive distillationand to the product produced by such redistillation, and has for its object to produce from such products, which are necessarily character ized by creosote or tarry odor and by heavy residual matter, as to render them incapable of use except for preserving wood or other material and for otheruses in which their odor is not ob ectionable, oils which are clear, viscid, free from creosote or creosote odor and capable of use for purposes such as those for which socalled rosin oilis used. By the use of our invention it is possible to produce from such products of destructive distillation, which, by reason of their characteristics and limited use, are of comparatively little value, oils which are .of comparatively high value to an amount which is a considerable fraction of the amount of the original product treated and at the same time to'leave the remainder in suchcondition that it will be capable of the uses for which the original product was adapted. In other words, by the use of our'invention a,

In carrying out our invention no particu-l lar apparatus is required other than a still and condenser of ordinary construction, except that the means for heating the still must be so arranged as to be capable of regulation, so as to distil off successive prod- 'ucts' at successive definite temperatures.

The product to be treated may be creosote oil, pitch or tar produced from pine or other resinous wood by destructive distilla- Specification of Letters Patent. P t t d N 30, 1915 Application filed April 17, 1915. Serial No. 22,030. I i

tion; that is, by distillation at a temperature sufliciently high to cause. destructive distillation and the consequent formation of pyroligneous acid or wood creosote or like substances characterized by What is com monly termed a creosote odor. This product 1s placed in-the stilland the contents are first heated to a temperature not over 500 degrees F ahrenheit-and maintained at this temperature until the substances which volatilize at this temperature are driven ofi. The substances so driven off when condensed form .a light oil which carries a strong creosote odor and what is'left in the still is free from such odor. After this first fractional distillate is driven oil the contents of the still are heated to a temperature not exceedas long a period as may be found practicable, so as to recover as much of this oil resembling rosin oil as can be recovered Without too great cost of time and heat, the heat ing is discontinued and the residue if any, which remains in the still as a thick tarry substance when hot, but solid when cold should be removed while hot and should preferably be mixed with the light creosote oil obtained as the first fractional distillate.

hen this residue and the light creosote oil are mixed together a product is formed adapted for the uses for which the ordinary creosote oil is adapted, having the preservative qualities of ordinary creosote oil and having a consistency more or less like that of ordinary creosote oil, depending somewhat on the proportions of light creosote oil and final residue obtained.

'VVhen ordinary creosote oil is used as the material to which our process is applied, a larger proportion of light creosote oil is produced than when pitch or tar is used and less of this product will be obtained from pitch than from tar, and, of course, when the material treated consists of a mixture of creosote oil, pitch and tar, the proportion of light creosote oil produced will depend upon the proportionate content of this substance produce a'clear, viscid oil free from creosote odor, which consists in heating such product to a temperature not eiiceeding 500 degrees Fahrenheit and maintaining it vat such temperature until all substances having creosote oil have been distilled oil, and then raising the temperature to not exceeding 700 degrees Fahrenheit and distilling off oil free from creosote odor.

2. The process of treating pitch and tar obtained by destructive distillation or resinous ood, which consists in heating the pitch or tar to a temperature not exceeding 500 degrees Fahrenheit and maintaining it at such temperature until all substances having creosote odor have been distilled off and then raising the temperature to not exceeding 700 degrees F ahrenheit and distilling oil oil free from creosote odor. 1

This specification signed and witnessed this "18th'day. of May, A. D. 1914.

/ HAROLD M. CHASE.

JOHN L.'G RAFFLIN. In the presence of C. H. HARRISS, M. I. HARRISS. 

